One fun thing about this. There's this teacher that I met in middle school who also knows this trick. I'm Chinese, that guy too. He was old (in his 70s) and he

One fun thing about this. There's this teacher that I met in middle school who also knows this trick. I'm Chinese, that guy too. He was old (in his 70s) and he definitely didn't know how MIT does it so this is a common trick around the world in some way.